The airline said Flight 2555 was operating between Miami and Newark and landed safely at 3:28 p.m. There were 95 passengers and six crew members aboard. No one was injured.
American said the plane’s captain declared an emergency as a precautionary measure and shut down an engine for the final 20 minutes of the flight.
Jessica Kowal, a Boeing spokeswoman, said the company was aware of the incident and referred questions to American.
American was the first U.S. carrier to resume flying the Boeing 737 Max after the Federal Aviation Administration lifted its ban on the jet in November.
The agency grounded the jetliner in March 2019, after a Boeing 737 Max operated by Ethiopian Airlines crashed shortly after takeoff. It was the second crash in less than five months involving the plane. A flight operated by Lion Air crashed into the Java Sea in October 2018.
In all, 346 people died in the crashes.